The objective of the proposed research project is to study the materials and methods of hearing aid evaluation and aural rehabilitation for patients with severe and profound hearing impairment. Hearing aid evaluations based primarily on patient responses to speech stimuli will lead to selection of an appropriate hearing aid or a decision against use of an aid. Patients fitted wth a hearing aid will enter an aural rehabilitation (AR) program that will include programmed instruction in auditory training and group interaction for communication skills in addition to speech reading and individual counseling. These patients seem especially disadvantaged in that many have not been able to adjust to hearing aid use and they often excluded from AR group work by virtue of the severity of their loss. The project should provide a fairly objective evaluation of their problems with hearing aids and the kind of aural rehabilitation procedures that are most helpful to them. Findings should be directly applicable to young children with similar hearing loss and also relevant to the recent interest in cochlear implants for patients with profound hearing loss: these patients may be faced in the near future with a choice between an implant and a hearing aid; in any case, they will probably need a program of aural rehabilitation.